Porcupine rollers

ABSTRACT

A porcupine roller wherein the roller body has needle bars releasably attached to the surface. Outwardly pointing needles are mounted on the needle bars. The roller body has on its outer surface a plurality of retaining grooves extending substantially parallel to the axis of rotation of the roller body. The cross section of the needle bars fits the cross section of the grooves so that the needle bars may be inserted into the grooves and held securely against displacement in the direction of rotation of the roller body. Means are provided for adjusting the position of the needle bars in the axial direction of the roller body.

United States Patent Burckhardt et a1.

[ Mar. 7, 1972 [54] PORCUPINE ROLLERS [72] Inventors: Christoph Burckhardt, Binningen; Walter Glaser, Allschwil, both of Switzerland [30] Foreign Application Priority Data Jan. 31, 1969 Switzerland 1557/69 [56] References Cited UNITED STATES PATENTS 1,431,904 10/1922 Bohmer ..19/234 3,123,866 3/1964 Stewart et a1 .19/97 2,940,129 6/1960 Stewart ..19/1 15 FOREIGN PATENTS 0R APPLICATIONS 552,414 6/1932 Germany 19/97 693 1854 Great Britain ..19/ 128 3,056 1863 Great Britain ..l9/112 707,115 5/1966 Italy 19/97 Primary Examiner-Dorsey Newton Allurnoy- Wenderoth. l .ind & lonuck [57] ABSTRACT A porcupine roller wherein the roller body has needle bars releasably attached to the surface. Outwardly pointing needles are mounted on the needle bars. The roller body has on its outer surface a plurality of retaining grooves extending sub stantially parallel to the axis of rotation of the roller bodyv The cross section of the needle bars fits the cross section of the grooves so that the needle bars may be inserted into the grooves and held securely against displacement in the direction of rotation of the roller body. Means are provided for adjusting the position of the needle bars in the axial direction of the roller body.

7 Claims, 14 Drawing Figures Pmimmm m2 8,646,639

SHEET 1 {1F 2 INVENTORS CHRISTIAN BUR. '=v' WALTER GLASER BY Jim 5W ATTORNEYS PATENTEUMAR (I972 3,646,639

SHEET 2 0r 2 'I mw z- 30 INVENTORS CHRISTIAN BURCKHARDT FIGBC WALTER GLASER ATTORNEYS PORCUPINE ROLLERS In the textile industry and also in related fields, porcupine rollers are known which have a roller substantially in the form of a hollow cylinder normally of brass whose periphery is provided with outwardly pointing needles. Such porcupine rollers have found a wide field of application in transporting, perforating, combing and stretching and recently have been used for fibrillating plastic sheets.

Hitherto when using these porcupine rollers, the roller body has been provided with a large number of small radial or inclined holes, in which slightly conical needles are fixed from the inside or from the outside, and are securely fixed by pressure.

The replacement of needles mounted in this way is difficult and the time consuming. If the needles are damaged or worn,

they must be chemically removed, or knocked out in the direction of the holes in the roller, which latter often results in the breaking of the relatively firmly fixed needles. Also, the holes, after the removal of the needles, are somewhat widened so that only needles of a larger diameter can subsequently be securely mounted and this can unfavorably affect the work the roller is intended to perform.

These disadvantages can be avoided according to the present invention by mounting the needles on needle bars which in turn are removably secured to the surface of the porcupine roller.

Advantageously the roller body is provided on its cylindrical exterior surface with a number of retaining grooves which run substantially parallel to the axis of the roller and the cross sections of the needle bars fit into those of the grooves so that the needle bars can be pushed into the grooves and there fixed against any forces acting in the direction of rotation of the roller.

In a preferred embodiment, the retaining grooves have a dovetail cross section.

Alternatively the needle bars can be screwed on to the surface of the roller body. In such an embodiment, each needle bar can be provided with two parallel sections connected to each other by a bridge, one section being used to anchor the needle bar to the roller body and the other to accommodate the needles.

Embodiments of porcupine roller in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 shows part of one end of a roller in which a needlebar is being inserted into a dovetail-section groove on the periphery of the roller,

FIGS. 2a and 2b are cross sections of needle bars,

FIG. 3 shows a roller with needle bars which can be screwed in place,

FIG. 4 shows, in cross section, one of the needle bars represented in FIGURE 3,

FIG. 5 illustrates a modified construction with screw-on needle bars,

FIG. 6 is a cross section of a roller, the needle bars being shown without needles,

FIG. 7a and 7b illustrate a cross-sectional view, on an enlarged scale, of a further embodiment of porcupine roller permitting adjustment of the angle of the needles, and

FIGS. 8a to 10 show, in cross section, further embodiments permitting easy displacement of the needle bars in the axial direction of the roller.

In FIG. 1 one end portion of a porcupine roller is shown, the numeral 1 generally denoting the roller. This roller has a roller-body 2 of substantially hollow-cylindrical form with a plurality of dovetail-shaped retaining grooves 3 around its periphery. The grooves 3 run parallel to the main axis of the roller, and are uniformly spaced around the periphery of the roller body 2. A metal needle bar 4, whose cross section corresponds to that of the dovetail grooves 3, bears a number of needles 5 arranged in a straight line. The needles 5, which in their lower parts have a slightly conical shape, extend through cylindrical holes provided in the needle bars 4 and are held firmly on account of their conical shape. The exterior dimensions of the needle bars 4 are selected so that each needle bar may be inserted into a groove 3 of the roller body 2 and then secured in place. Since during use of the porcupine roller virtually no axially directed forces act on the needle bars 4, these do not need to be secured by further securing members. The lateral securing of the needle bars 4 using a flange ring or similar securing element is also possible.

In case of damage or wear of one or more needles 5, the whole row of needles can easily and quickly be exchanged by simple replacement of the corresponding needle bar 4. Also it is possible without difficulty, if the need arises, to replace all the needle bars 4 of a porcupine roller by other needle bars provided with needles of a different size. Also the total number of needles on a porcupine roller can, if desired, be reduced e.g., halved by removal of every second needle bar. The empty grooves are then preferably filled with blind bars (i.e. needleless bars). Detailed sections of two forms of needle bar 4 are shown in FIGS. 20 and 2b. Shapes other than a dovetail shape can be considered for the grooves, provided foolproof securing of the needle bars 4 on the roller body 2 is possible. Also the securing of the needles in the needle bars 4 can be accomplished in any desired manner for example by soldering or adhesively securing.

In the embodiment shown in FIG. 3, the grooves 6 in the outer periphery of the roller body 2 are of substantially rectangular cross section. Each of the corresponding needle bars 7 (see FIG. FIGURE 4) is provided with two parallel longitudinal sections 9a and 9b which are connected to each other by a bridge 8. This section 9a serves to anchor the needle bar on the roller body and the section 9b serves to accommodate the needles 5. Because of the rectangular form of the grooves 6, the needle bars 7, in contrast to the embodiment according to FIG. 1, must be fastened to the roller body 2. This can be accomplished by means of easily disconnectable fastening elements, advantageously by means of screws I0, which can be screwed into corresponding threaded holes provided in the base of each groove.

FIG. 5 shows the end portion of a porcupine roller with two needle bars 7 screwed onto an ungrooved roller body.

The cross section of the needle bars shown in FIG. 4 has been approved in practice. It would theoretically, however, also be possible to have the needle bars of simple rectangular cross section and to screw these onto the roller body.

The grooves 6 both in this embodiment and in the embodiment of FIG. 3 are not absolutely necessary.

The great advantage of the porcupine rollers described is displayed especially in fibrillating plastics sheets in which the needles of the needle bars are subjected to severe demands. By holding in stock a complete replacement needle-bar relatively expensive bronze or brass roller bodies 2 can be used for a long time, the needle bars being replaced from time to time.

A further possibility for securing the needle bars 4 in the grooves 3 resides in the use of a resilient action in which the longitudinal sides of each needle-bar are pressed against the neighboring walls of the groove.

This is effected by providing a longitudinal groove (13 in FIG. 2b) in the base of each needle bar so that inserting the needle bar can be facilitated by pressing together the feet of the needle bar.

The needle bars 4 can have a tolerance relative to the grooves. To adjust for this tolerance and hold each needle bar securely in position, an adjusting means can be placed in the groove, for example a metal or plastics wire or a strip of any suitable material. This adjusting means can either lie only on the base of the groove, (as denoted by numeral 11 in FIG. 1) or (for example as shown by numeral 12 in FIG. 2b can also extend up the longitudinal sides of the needle bar.

FIG. 6 of the drawings shows a simplified section of the roller-body 2 carrying needle bars 14 on its periphery. These needle bars 14, whose needles for the sake of simplicity are not shown, are held at either end by a ring 15 which is screwed into place.

The needles 5 (FIGS. 2a, 2b and 4) of the needle bars must often be inclined at an angle to the corresponding radius of the porcupine roller. This means that the needles are not placed perpendicularly in the corresponding needle bar (as in FIGS. 2a) but at an angle (as in FIGS. 2b and 4).

A particular orientation of inclined needles in a needle bar can only be used for a quite limited number of applications, for example for fibrillating special materials, and when changing from one material to another the needle bars must be replaced by others with a different inclination of the needles. This disadvantage is overcome by the embodiment shown in FIGS. 7a and 7b. On the periphery of a roller body 16 (only part of which is shown) a needle bar 17 is inserted in a dovetail groove. The numeral 18 denotes an extension of a radius of the roller radius through the needle bar 17, the axis of symmetry of the needle bar is devoted by 19 and the extension of the axis of the needles by 20. The symmetry axis 19 and the extension of the radius 18 form an angle a which can also be measured between a line 21 defining the lower boundary of the needle bar and a line 22 perpendicular to the roller radius. The needle axis 20 is displaced by an angle [3 from the axis of symmetry 19 of the needle bar, which can either equal the angle nor can differ therefrom.

In the orientation of the needle bar shown in FIG. 7a, the two angles a and B add up to a total angle at which the needles are inclined to the extension of the roller radius 18. If however, the needle bar 17 is reversed in the dovetail groove, so that its longitudinal sides are interchanged, the angles a and B are subtracted from each other and a new angle of inclination of the needles results. In the embodiment according to FIGS. 7a and 7b, the angle a is equal to the angle B, so that the needle axis, on reversal of the needle bar 17, as shown in FIGS. 7b, coincides with the extension 18 of the roller radius.

By virtue of this arrangement, the user of the porcupine roller described has available two different needle angles and needs only to obtain a single set of needle bars.

According as the angles a and B are selected as equal or different, a reversal of the needle bars 17 gives a zero needle inclination (FIG. 71;) or a desired angle given by the difference of the angles a and ,8.

In numerous cases, it is desired and advantageous, that the needles of adjacent needle bars should lie (in the direction of rotation of the porcupine roller) not exactly in line with each other, but be displaced with reference to each other. Since this, however, is not true for all cases, and the optimum measurement of the degree of displacement can alter from case to case, it would be advantageous if the individual needle bars could be displaced in the direction of their own longitudinal axis.

An embodiment permitting such arrangement is illustrated in the embodiments shown in FIGS. 8a to of the drawings.

FIGS. 8a to Sc show the roller body 2 on which a needle bar 23 is provided in a dovetail groove. Fastened on one end face of the roller body 2 by means of screws 25, is a holding ring 24. Adjacent to the outer periphery of the holding ring 24, the roller body is provided with an annular recess 26 which is located adjacent to the end-face of the roller body.

A number of blind holes 27, uniformly spaced around the periphery of the roller body 2 are provided in one end-face of the roller body, one-half 27a of the cross section of each hole being provided in the roller-body 2 and the other half 27b being provided in the needle bar 23. Only that half 27b of the hole provided in the needle bar 23 is threaded, the other half 270 being unthreaded and corresponding in radius to a clearance hole for the thread.

As FIG. 8b shows, the outer edge of the retaining ring 24 is provided with an upwardly open U-shaped recess 28 through which the shaft 29 of a bolt 30 extends. The head 3] of the bolt abuts the outer surface of the retaining ring 24, while a collar 32 formed on the shaft of the bolt lies close to the inner surface of the retaining ring 24. Turning the bolt 30, via its head 31, causes the bolt to move the needle bar 23 in the direction of its longitudinal axis, the bolt itself being held substantially without axial translation, within the recess 28. In this manner the position of the needle bar 23 on the roller body 2 can be adjusted with great precision, the threaded part of the bolt 30 making driving engagement with the needle bar 23 inside the half 27b of the hole while the bolt freely rotates in the other half 37a of the hole.

According to FIG. 9, a retaining ring 33 is fastened with screws 34 to one end-face of the roller body 2. The shaft 35 of an adjusting bolt 36 is provided with a wasted portion adjacent to its head which cooperates with the U-shaped recess of the retaining ring 33 to hold the bolt 36 against axial translation during rotation thereof whereby the needle bar 37 is moved axially by the threaded part of the bolt 36.

A further variation is illustrated in simplified form in FIGURE 10. In this case the roller body 2 is provided with a number of holes 38 corresponding to the holes 27 of FIGS. 8b and 9. The rim of the roller-body 2 is here however provided with a slot 39, which is spaced inwardly a short distance from the end of the roller body. Into this slot 39 there partially extends the flange 40 of a threaded adjusting member 41. On rotation of the member 41 via a square-ended projection 42, the member 41 remains without translatory movement, while the needle bar is moved along as it engages with the screw thread of the adjusting member 41.

A scale 43 can be provided on the head of the adjusting member 41 between the flange 40 and the projection 42, to permit an exact and reproducible positioning of the needle bar.

What is claimed is:

l. A porcupine roller comprising a roller body, needle bars releasably attached to the surface of said roller body, outwardly pointing needles mounted on said needle bars, said roller body having on its outer surface a plurality of retaining grooves extending substantially parallel to the axis of rotation of said roller body, the cross section of said needle bars fitting the cross section of said grooves so that said needle bars may be inserted into said grooves and held securely against displacement in the direction of rotation of said roller body, and means for adjusting the position of said needle bars in the axial direction of said roller body.

2. A porcupine roller according to claim 1 wherein each needle bar is provided on its lower surface with a longitudinal groove separating leg portions thereof allowing a movement of the leg portions of the needle bar towards each other during mounting of the needle bar in a groove in the roller body so that the needle bar is held firmly in position on account of its resilience.

3. A porcupine roll according to claim 1 wherein said needle bars are inclined at an angle to the radius of said roller body and said needles are inclined with respect to said needle bars.

4. A porcupine roller according to claim 3 wherein the angle between the axis of symmetry of the needle bar and the axis of the needles equals the angle between the axis of symmetry of the needle bar and the radius of said roller body.

5. A porcupine roller according to claim 1 wherein an endface of said roller has a plurality of semicircular grooves parallel to the axis of rotation of said roller body, each of said needle bars having threaded semicircular grooves cooperating with said first named grooves to form a hole, an inner portion of said hole being unthreaded and having a somewhat greater diameter, a threaded adjusting member located in each of said holes without undergoing translational movement whereby each of said needle bars can be displaced in the direction of its longitudinal axis by rotation of said adjusting member.

6. A porcupine roller according to claim 5 wherein said ad justing member is retained by a retaining ring fixed to said roller-body.

7. A porcupine roller according to claim 5 wherein said roller-body has a slot extending in a peripheral direction of said roller-body, and each adjusting member is provided with a flange which locates in said slot. 

1. A porcupine roller comprising a roller body, needle bars releasably attached to the surface of said roller body, outwardly pointing needles mounted on said needle bars, said roller body having on its outer surface a plurality of retaining grooves extending substantially parallel to the axis of rotation of said roller body, the cross section of said needle bars fitting the cross section of said grooves sO that said needle bars may be inserted into said grooves and held securely against displacement in the direction of rotation of said roller body, and means for adjusting the position of said needle bars in the axial direction of said roller body.
 2. A porcupine roller according to claim 1 wherein each needle bar is provided on its lower surface with a longitudinal groove separating leg portions thereof allowing a movement of the leg portions of the needle bar towards each other during mounting of the needle bar in a groove in the roller body so that the needle bar is held firmly in position on account of its resilience.
 3. A porcupine roll according to claim 1 wherein said needle bars are inclined at an angle to the radius of said roller body and said needles are inclined with respect to said needle bars.
 4. A porcupine roller according to claim 3 wherein the angle between the axis of symmetry of the needle bar and the axis of the needles equals the angle between the axis of symmetry of the needle bar and the radius of said roller body.
 5. A porcupine roller according to claim 1 wherein an end-face of said roller has a plurality of semicircular grooves parallel to the axis of rotation of said roller body, each of said needle bars having threaded semicircular grooves cooperating with said first named grooves to form a hole, an inner portion of said hole being unthreaded and having a somewhat greater diameter, a threaded adjusting member located in each of said holes without undergoing translational movement whereby each of said needle bars can be displaced in the direction of its longitudinal axis by rotation of said adjusting member.
 6. A porcupine roller according to claim 5 wherein said adjusting member is retained by a retaining ring fixed to said roller-body.
 7. A porcupine roller according to claim 5 wherein said roller-body has a slot extending in a peripheral direction of said roller-body, and each adjusting member is provided with a flange which locates in said slot. 